<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<style type="text/css">
    /* @mixin juzhong（$w,
    $w） {
        width: $w;
        height: $w;
    } */

    .content {
        /* @include juzhong(300px, 300px); */
        width: 300px;
        height: 300px;
        margin: 0 auto;
    }

    .content img {
        width: 100%;
        height: 100%;
    }

    .image {
        width: 300px;
        height: 300px;
        background-color: black;
        margin-top: 30px;
        position: relative;
        left: 50%;
        transform: translate(-50%, 0px);
        background-image: url(qb.jpg);
        background-size: 100% 100%;

    }
</style>

<body>
    <div class="content">
        <img src="qb.jpg" alt="">
    </div>
    <div class="image"></div>
</body>

</html>